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941.
Peter C. Zee Helena Mendes‐Soares Yuen‐Tsu N. Yu Susanne A. Kraemer Heike Keller Stephan Ossowski Korbinian Schneeberger Gregory J. Velicer 《Evolution; international journal of organic evolution》2014,68(9):2701-2708
Although the importance of epistasis in evolution has long been recognized, remarkably little is known about the processes by which epistatic interactions evolve in real time in specific biological systems. Here, we have characterized how the epistatic fitness relationship between a social gene and an adapting genome changes radically over a short evolutionary time frame in the social bacterium Myxococcus xanthus. We show that a highly beneficial effect of this social gene in the ancestral genome is gradually reduced—and ultimately reversed into a deleterious effect—over the course of an experimental adaptive trajectory in which a primitive form of novel cooperation evolved. This reduction and reversal of a positive social allelic effect is driven solely by changes in the genetic context in which the gene is expressed as new mutations are sequentially fixed during adaptive evolution, and explicitly demonstrates a significant evolutionary change in the genetic architecture of an ecologically important social trait. 相似文献
942.
943.
944.
Márcio L. Tomaz Beatriz M. Januzzi Mendes francisco De Assis A. Mourão Filho Clarice G. B. Demétrio Naratip Jansakul Adriana P. Martinelli Rodriguez 《In vitro cellular & developmental biology. Plant》2001,37(4):446-452
Summary Somatic embryogenesis from nucellus-derived callus cultures of five cultivars, including three (Caipira, Seleta Vermelha,
and Valencia) of sweet oranges (C. sinesis L. Osbeck), Rangpur lime (C. limonia L. Osbeck), and Cleopatra mandarin (C. reticulata Blanco) (lines I and II), were studied. Callus lines maintained on MT medium supplemented with 50 g l−1 sucrose were transferred to MT medium supplemented with different carbohydrate sources: galactose, glucose, lactose, maltose,
or sucrose at 18, 37, 75, 110, or 150 mM, or glycerol at 6, 12, 24, 36, or 50 mM. Globular embryos were observed after approximately 4 wk, in several treatments. Cultures of Valencia and Caipira sweet oranges
and Cleopatra mandarin (line I) showed high numbers of embryos on medium containing galactose, lactose, and maltose. Histological
studies showed somatic embryos in all developmental stages with a normal histodiffeentiation pattern. The other two cultivars
(Rangpur lime and Cleopatra mandarin, line II) formed very few embryos, which did not develop further following the globular
stage. Some of the abnormalities observed were lack or dedifferentiation of protoderm and absence of apical meristems and
procambial strands. Embryos that followed the normal sequence of development were easily converted into plants. Non-embryogenic
cultures continued as proliferating callus cultures, eventually forming a few embryos which did not convert into plants. Statistical
analyses of the callus response to carbohydrate treatments was done using an overdispersion Poisson model. 相似文献
945.
Ubiana de Cássia Silva Gilberto de Oliveira Mendes Nina Morena R. M. Silva Josiane Leal Duarte Ivo Ribeiro Silva Marcos Rogério Tótola Maurício Dutra Costa 《PloS one》2014,9(10)
P-solubilizing microorganisms are a promising alternative for a sustainable use of P against a backdrop of depletion of high-grade rock phosphates (RPs). Nevertheless, toxic elements present in RPs, such as fluorine, can negatively affect microbial solubilization. Thus, this study aimed at selecting Aspergillus niger mutants efficient at P solubilization in the presence of fluoride (F−). The mutants were obtained by exposition of conidia to UV light followed by screening in a medium supplemented with Ca3(PO4)2 and F−. The mutant FS1-555 showed the highest solubilization in the presence of F−, releasing approximately 70% of the P contained in Ca3(PO4)2, a value 1.7 times higher than that obtained for the wild type (WT). The mutant FS1-331 showed improved ability of solubilizing fluorapatites, increasing the solubilization of Araxá, Catalão, and Patos RPs by 1.7, 1.6, and 2.5 times that of the WT, respectively. These mutants also grew better in the presence of F−, indicating that mutagenesis allowed the acquisition of F− tolerance. Higher production of oxalic acid by FS1-331 correlated with its improved capacity for RP solubilization. This mutant represents a significant improvement and possess a high potential for application in solubilization systems with fluoride-rich phosphate sources. 相似文献
946.
Freire Filho Robrio Inforzato Igor Tabacow Fernanda P. Martins Waldney Possamai Carla B. Ferraz Daniel Hack Robson O. E. Rocha Samantha Slomp Daniel V. Nery Marcello S. Almeida Letcia Fernandes Nala Alves Pedro Paulo Rezende Mendes Srgio L. Strier Karen B. 《Primates; journal of primatology》2022,63(4):335-342
Primates - Primate thanatology, or the study of primate responses to dying and death, has become increasingly relevant in recent years. However, the number of reports remains small and the quality... 相似文献
947.
Oliveira Samara Rodrigues Bonfim Damasceno Franco Álvaro Xavier Quaresma Marielle Pires de Carvalho Cecília Mendes Morais da Cunha Jácome Marques Fabrícia da Silva Pantoja Patrícia Mendonça Vanessa Azevedo da Silva Osterne Vinicius José Correia Jorge Luis Almeida Assreuy Ana Maria Sampaio de Souza Marcellus Henrique Loiola Pontes do Nascimento Kyria Santiago Cavada Benildo Sousa Criddle David Neil Soares Pedro Marcos Gomes 《Glycoconjugate journal》2022,39(5):599-608
Glycoconjugate Journal - Lectins isolated from Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr) are promising molecules to prevent cell death. Acute pancreatitis, characterized by... 相似文献
948.
Jarina Pena DaMata Bárbara Pinheiro Mendes Kátia Maciel-Lima Cristiane Alves Silva Menezes Walderez Ornelas Dutra Lirlandia Pires Sousa Maria Fátima Horta 《PloS one》2015,10(10)
Leishmania is an intracellular parasite in vertebrate hosts, including man. During infection, amastigotes replicate inside macrophages and are transmitted to healthy cells, leading to amplification of the infection. Although transfer of amastigotes from infected to healthy cells is a crucial step that may shape the outcome of the infection, it is not fully understood. Here we compare L. amazonensis and L. guyanensis infection in C57BL/6 and BALB/c mice and investigate the fate of macrophages when infected with these species of Leishmania in vitro. As previously shown, infection of mice results in distinct outcomes: L. amazonensis causes a chronic infection in both strains of mice (although milder in C57BL/6), whereas L. guyanensis does not cause them disease. In vitro, infection is persistent in L. amazonensis-infected macrophages whereas L. guyanensis growth is controlled by host cells from both strains of mice. We demonstrate that, in vitro, L. amazonensis induces apoptosis of both C57BL/6 and BALB/c macrophages, characterized by PS exposure, DNA cleavage into nucleosomal size fragments, and consequent hypodiploidy. None of these signs were seen in macrophages infected with L. guyanensis, which seem to die through necrosis, as indicated by increased PI-, but not Annexin V-, positive cells. L. amazonensis-induced macrophage apoptosis was associated to activation of caspases-3, -8 and -9 in both strains of mice. Considering these two species of Leishmania and strains of mice, macrophage apoptosis, induced at the initial moments of infection, correlates with chronic infection, regardless of its severity. We present evidence suggestive that macrophages phagocytize L. amazonensis-infected cells, which has not been verified so far. The ingestion of apoptotic infected macrophages by healthy macrophages could be a way of amastigote spreading, leading to the establishment of infection. 相似文献
949.
Nadini Oliveira Martins Renata Torres de Souza Esteban Mauricio Cordero Danielle Cortez Maldonado Cristian Cortez Marjorie Mendes Marini Eden Ramalho Ferreira Ethel Bayer-Santos Igor Correia de Almeida Nobuko Yoshida José Franco da Silveira 《PLoS neglected tropical diseases》2015,9(11)
Background
The surface coat of Trypanosoma cruzi is predominantly composed of glycosylphosphatidylinositol-anchored proteins, which have been extensively characterized. However, very little is known about less abundant surface proteins and their role in host-parasite interactions.Methodology/ Principal Findings
Here, we described a novel family of T. cruzi surface membrane proteins (TcSMP), which are conserved among different T. cruzi lineages and have orthologs in other Trypanosoma species. TcSMP genes are densely clustered within the genome, suggesting that they could have originated by tandem gene duplication. Several lines of evidence indicate that TcSMP is a membrane-spanning protein located at the cellular surface and is released into the extracellular milieu. TcSMP exhibited the key elements typical of surface proteins (N-terminal signal peptide or signal anchor) and a C-terminal hydrophobic sequence predicted to be a trans-membrane domain. Immunofluorescence of live parasites showed that anti-TcSMP antibodies clearly labeled the surface of all T. cruzi developmental forms. TcSMP peptides previously found in a membrane-enriched fraction were identified by proteomic analysis in membrane vesicles as well as in soluble forms in the T. cruzi secretome. TcSMP proteins were also located intracellularly likely associated with membrane-bound structures. We demonstrated that TcSMP proteins were capable of inhibiting metacyclic trypomastigote entry into host cells. TcSMP bound to mammalian cells and triggered Ca2+ signaling and lysosome exocytosis, events that are required for parasitophorous vacuole biogenesis. The effects of TcSMP were of lower magnitude compared to gp82, the major adhesion protein of metacyclic trypomastigotes, suggesting that TcSMP may play an auxiliary role in host cell invasion.Conclusion/Significance
We hypothesized that the productive interaction of T. cruzi with host cells that effectively results in internalization may depend on diverse adhesion molecules. In the metacyclic forms, the signaling induced by TcSMP may be additive to that triggered by the major surface molecule gp82, further increasing the host cell responses required for infection. 相似文献950.
José Maria Rodrigues da Luz Sirlaine Albino Paes Karla Veloso Gon?alves Ribeiro Igor Rodrigues Mendes Maria Catarina Megumi Kasuya 《PloS one》2015,10(6)
We studied the biodegradation of green polyethylene (GP) by Pleurotus ostreatus. The GP was developed from renewable raw materials to help to reduce the emissions of greenhouse gases. However, little information regarding the biodegradation of GP discarded in the environment is available. P. ostreatus is a lignocellulolytic fungus that has been used in bioremediation processes for agroindustrial residues, pollutants, and recalcitrant compounds. Recently, we showed the potential of this fungus to degrade oxo-biodegradable polyethylene. GP plastic bags were exposed to sunlight for up to 120 days to induce the initial photodegradation of the polymers. After this period, no cracks, pits, or new functional groups in the structure of GP were observed. Fragments of these bags were used as the substrate for the growth of P. ostreatus. After 30 d of incubation, physical and chemical alterations in the structure of GP were observed. We conclude that the exposure of GP to sunlight and its subsequent incubation in the presence of P. ostreatus can decrease the half-life of GP and facilitate the mineralization of these polymers. 相似文献